Global radiation is crucial for the planning of any photovoltaic system. It influences the yield achieved and therefore plays a key role in the profitability of a PV system. Here you can find out how high the global radiation is in Germany and what influence it has on a PV system.
What is global radiation?
Global radiation is the solar radiation that reaches the earth's surface horizontally. It includes both direct and diffuse solar radiation. Global radiation is measured in watts per square meter. Global radiation is stronger the closer you get to the equator.
Global radiation consists of direct radiation and diffuse radiation.
- Direct radiation is the solar radiation that reaches the earth’s surface directly.
- Diffuse radiation is solar radiation that does not come directly from the sun. The sun's rays are absorbed and scattered by clouds, aerosols, air molecules and particles in the atmosphere on their way to the earth's surface.
How is global radiation measured?
For measuring global radiation, mostly pyranometer A pyranometer measures sunlight by heating a blackened plate. The temperature difference determines the irradiance. Regular calibration and cleaning ensure accurate measurements, but can be expensive.
Other options for measuring global radiation include silicon radiation sensors and the evaluation of satellite images.
How high is the global radiation in Germany?
Global radiation in Germany is between 1,000 and 1,300 kWh/m². The average instantaneous value is approximately 133.67 W/m² and the total value is around 1,171 kWh/m².
The following map from the German Weather Service shows the distribution of global radiation in Germany.
